U.S. patent application number 14/766275 was filed with the patent office on 2016-01-14 for non-aqueous oral care compositions.
This patent application is currently assigned to CONOPCO, INC., D/B/A UNILEVER, CONOPCO, INC., D/B/A UNILEVER. The applicant listed for this patent is CONOPCO, INC., D/B/A UNILEVER, CONOPCO, INC., D/B/A UNILEVER. Invention is credited to Anne-Laure Sophie FERRY, Brian Joseph GROVES.
Application Number | 20160008255 14/766275 |
Document ID | / |
Family ID | 47710005 |
Filed Date | 2016-01-14 |
United States Patent
Application |
20160008255 |
Kind Code |
A1 |
FERRY; Anne-Laure Sophie ;
et al. |
January 14, 2016 |
NON-AQUEOUS ORAL CARE COMPOSITIONS
Abstract
The invention provides a non-aqueous oral care composition
suitable for cleaning the surfaces of the oral cavity, the
composition comprising: (a) from 20 to 90 wt % (by weight by based
on the total weight of the composition) of one or more organic
polyols having 3 or more hydroxyl groups in the molecule; (b) from
3 to 75 wt % (by weight based on the total weight of the oral care
composition) of one or more particulate abrasive cleaning agents;
(c) from 0.2 to 5 wt % (by weight based on the total weight of the
oral care composition) of one or more surfactants, and (d) from
0.01 to 5 wt % (by weight based on the total weight of the oral
care composition) of xanthan gum. The composition is easy to
manufacture without the need for careful temperature control. It is
also un expectedly stable and cost-effective, with suitable
viscosity characteristics despite its non-aqueous nature.
Inventors: |
FERRY; Anne-Laure Sophie;
(Southport, Merseyside, GB) ; GROVES; Brian Joseph;
(Bebington, Wirral, Merseyside, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CONOPCO, INC., D/B/A UNILEVER |
Englewood Cliffs |
NJ |
US |
|
|
Assignee: |
CONOPCO, INC., D/B/A
UNILEVER
ENGLEWOOD CLIFFS
NJ
|
Family ID: |
47710005 |
Appl. No.: |
14/766275 |
Filed: |
February 10, 2014 |
PCT Filed: |
February 10, 2014 |
PCT NO: |
PCT/EP2014/052562 |
371 Date: |
August 6, 2015 |
Current U.S.
Class: |
424/57 |
Current CPC
Class: |
A61K 2800/28 20130101;
A61K 2800/48 20130101; A61K 8/345 20130101; A61K 8/24 20130101;
A61Q 11/00 20130101; A61K 8/25 20130101; A61K 8/463 20130101; A61K
8/73 20130101; A61K 2800/31 20130101 |
International
Class: |
A61K 8/73 20060101
A61K008/73; A61K 8/24 20060101 A61K008/24; A61K 8/25 20060101
A61K008/25; A61K 8/46 20060101 A61K008/46; A61Q 11/00 20060101
A61Q011/00; A61K 8/34 20060101 A61K008/34 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 14, 2013 |
EP |
13155197.0 |
Claims
1. A non-aqueous oral care composition suitable for cleaning the
surfaces of the oral cavity, the composition comprising: (a) from
20 to 9O wt % (by weight by based on the total weight of the
composition) of one or more organic polyols having 3 or more
hydroxyl groups in the molecule; (b) from 3 to 75 wt % (by weight
based on the total weight of the oral care composition) of one or
more particulate abrasive cleaning agents, (c) from 0.2 to 5 wt %
(by weight based on the total weight of the oral care composition)
of one or more surfactants, (d) from 0.01 to 5 wt % (by weight
based on the total weight of the oral care composition) of xanthan
gum and e) comprises a mixture of a calcium source and a phosphate
source in which the calcium source is calcium silicate.
2. A composition according to claim 1, in which the one or more
organic polyols having 3 or more hydroxyl groups in the molecule is
glycerol and the level of glycerol is from 60 to 75 wt % based on
the total weight of the composition.
3. A composition according to claim 1, in which the one or more
particulate abrasive cleaning agents are selected from abrasive
silicas and mixtures thereof.
4. A composition according to claim 1, in which the amount of
xanthan gum ranges from 0.1 to 0.9 wt % (by weight based on the
total weight of the oral care composition).
5. A composition according to claim 1, in which the amount of
additional polymeric thickening agents (with molecular weight
ranging from 1,000 to 5,000,000, and which are selected from
carboxyvinyl polymers, hydroxyalkyl cellulose derivatives, water
soluble salts of cellulose ethers, polyvinylpyrrolidone,
polyethylene glycols and mixtures thereof) is no more than 0.01 wt
% (by total weight additional polymeric thickening agents based on
the total weight of the composition).
6. A composition according to claim 1, which is in the form of a
dentifrice.
7. (canceled)
8. An oral care composition according to claim 1, in which the
phosphate source is a mixture of trisodium phosphate and monosodium
dihydrogen phosphate.
9. A process of preparing a non-aqueous oral care composition
suitable for cleaning the surfaces of the oral cavity, the process
comprising the steps of forming a mixture comprising: (a) from 20
to 90 wt % (by weight by based on the total weight of the
composition) of one or more organic polyols having 3 or more
hydroxyl groups in the molecule; (b) from 3 to 75 wt % (by weight
based on the total weight of the oral care composition) of one or
more particulate abrasive cleaning agents: (c) from 0.2 to 5 wt %
(by weight based on the total weight of the oral care composition)
of one or more surfactants, and (d) from 0.01 to 5 wt % (by weight
based on the total weight of the oral are composition) of xanthan
gum.
Description
FIELD OF THE INVENTION
[0001] The present invention is concerned with non-aqueous oral
care compositions.
BACKGROUND OF THE INVENTION
[0002] Oral care compositions such as dentifrices typically contain
dentally acceptable abrasive, humectant, water, and water-soluble
polymer which serves as a thickener and binder for the ingredients.
A variety of other ingredients such as flavours, sweeteners,
preservatives and fluoride are also utilized at low levels.
[0003] However there are many materials which are physically or
chemically incompatible with the aqueous environments found in
typical dentifrice formulations.
[0004] Non-aqueous formulations have been suggested as a way of
improving the stability of these materials. For example, U.S. Pat.
No. 4,071,615 describes anhydrous dentifrice compositions based on
glycerin, thickeners such as hydroxyethylcellulose and
carboxymethylcellulose, and silica.
[0005] Viscosity profile and flow characteristics are key factors
governing ease of processing, product performance and consumer
perception of a dentifrice. A problem with non-aqueous formulations
such as those disclosed in U.S. Pat. No. 4,071,615 is that they do
not behave rheologically like a typical aqueous dentifrice. In
particular they may exhibit insufficient consistency with a "runny"
character, leading to manufacturing difficulties and reduced
acceptance amongst consumers.
[0006] One way of improving the rheological behaviour of anhydrous
dentifrice formulations is described in WO2011/160996. According to
this publication, improved microstructure, ease of processing and
sensory properties are obtained by structuring the liquid
continuous phase with a crystalline structuring agent, such as one
or more solid polyethylene glycols having a melting point of
25.degree. C. or above.
[0007] However the preparation process described in WO2011/160996
requires carefully controlled heating and cooling stages in order
to ensure the formation of a crystalline network with the requisite
structuring properties.
[0008] The present inventors have found that the above problems may
be solved by the incorporation of xanthan gum as a structurant.
[0009] WO97/28783 describes xanthan gum as an ingredient in an oral
formulation based on 87 to 99% by weight anhydrous glycerin. The
formulation according to
[0010] WO97/28783 is a stable stannous fluoride gel which can be
extruded onto the bristles of a toothbrush. However, the
formulation is thickened with a polyethylene glycol 1000 thickener
in an amount of at least 3% by weight. It is also not suitable for
cleaning the surfaces of the oral cavity.
SUMMARY OF THE INVENTION
[0011] The present invention provides a non-aqueous oral care
composition suitable for cleaning the surfaces of the oral cavity,
the composition comprising: [0012] (a) from 20 to 90 wt % (by
weight by based on the total weight of the composition) of one or
more organic polyols having 3 or more hydroxyl groups in the
molecule; [0013] (b) from 3 to 75 wt % (by weight based on the
total weight of the oral care composition) of one or more
particulate abrasive cleaning agents; [0014] (c) from 0.2 to 5 wt %
(by weight based on the total weight of the oral care composition)
of one or more surfactants, and [0015] (d) from 0.01 to 5 wt % (by
weight based on the total weight of the oral care composition) of
xanthan gum.
[0016] Surprisingly, the oral care composition of the invention is
easy to manufacture without the need for careful temperature
control. It is also unexpectedly stable and cost-effective, with
suitable viscosity characteristics despite its non-aqueous
nature.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The composition of the invention is non-aqueous. The term
"non-aqueous" in the context of the present invention generally
means that water is not deliberately added to the composition in
any significant quantity. However, the term "non-aqueous" does not
mean that small amounts of water cannot be present, for example as
a consequence of its association with hygroscopic raw materials.
Accordingly, for the purposes of this invention, the term
"non-aqueous" generally means that water is present in an amount no
greater than about 5 wt %, more preferably no greater than about 3
wt % (by weight based on the total weight of the composition).
[0018] The composition of the invention comprises from 20 to 90 wt
% (by weight by based on the total weight of the composition) of
one or more organic polyols having 3 or more hydroxyl groups in the
molecule.
[0019] Preferred organic polyols having 3 or more hydroxyl groups
in the molecule (hereinafter termed "organic polyols"). for use in
the invention include glycerol, sorbitol, xylitol, mannitol,
lactitol, maltitol, erythritol, and hydrogenated partially
hydrolyzed polysaccharides. The most preferred organic polyol is
glycerol. Mixtures of any of the above described materials may also
be used.
[0020] The composition of the invention is most preferably organic
polyol-based. In the context of the present invention, the term
"organic polyol-based" generally means that the composition is not
oil-based or water-based, but instead organic polyol (as defined
above) forms a liquid continuous phase in which the particulate
ingredients of the composition (such as the one or more particulate
abrasive cleaning agents) are dispersed.
[0021] Ideally the composition of the invention is
glycerol-based.
[0022] The amount of organic polyol in the composition of the
invention suitably ranges from 35 to 90 wt %, preferably from 45 to
80 wt % (by total weight organic polyol based on the total weight
of the composition). More preferably the composition contains from
60 to 75 wt % glycerol based on the total weight of the
composition.
[0023] The composition of the invention comprises a particulate
abrasive cleaning agent in an amount of from 3 to 75 wt % (by
weight based on the total weight of the oral care composition).
Suitable particulate abrasive cleaning agents include abrasive
silicas, calcium carbonate, dicalcium phosphate, tricalcium
phosphate, calcined alumina, sodium and potassium metaphosphate,
sodium and potassium pyrophosphates, sodium trimetaphosphate,
sodium hexametaphosphate, particulate hydroxyapatite and mixtures
thereof. Preferred particulate abrasive cleaning agents for use in
the invention are selected from abrasive silicas such as silica
xerogels, hydrogels and aerogels and precipitated particulate
silicas and mixtures thereof.
[0024] Mixtures of any of the above described materials may also be
used.
[0025] The composition of the invention comprises one or more
surfactants in an amount of from 0.2 to 5 wt % (by weight based on
the total weight of the oral care composition) Suitable surfactants
include anionic surfactants, such as the sodium, magnesium,
ammonium or ethanolamine salts of C.sub.8 to 0.sub.18 alkyl
sulphates (for example sodium lauryl sulphate), C.sub.8 to C.sub.18
alkyl sulphosuccinates (for example dioctyl sodium
sulphosuccinate), C.sub.8 to C.sub.18 alkyl sulphoacetates (such as
sodium lauryl sulphoacetate), C.sub.8 to C.sub.18 alkyl
sarcosinates (such as sodium lauryl sarcosinate), C.sub.8 to
C.sub.18 alkyl phosphates (which can optionally comprise up to 10
ethylene oxide and/or propylene oxide units) and sulphated
monoglycerides. Other suitable surfactants include nonionic
surfactants, such as optionally polyethoxylated fatty acid sorbitan
esters, ethoxylated fatty acids, esters of polyethylene glycol,
ethoxylates of fatty acid monoglycerides and diglycerides, and
ethylene oxide/propylene oxide block polymers. Other suitable
surfactants include amphoteric surfactants, such as betaines or
sulphobetaines. Preferred surfactants for use in the invention are
selected from sodium lauryl sulfate, sodium lauryl sulfoacetate,
cocamidopropyl betaine, sodium alpha olefin sulfonate, dioctyl
sodium sulfosuccinate, sodium dodecyl benzene sulfonate and
mixtures thereof.
[0026] Mixtures of any of the above described materials may also be
used.
[0027] The composition of the invention comprises xanthan gum in an
amount of from 0.01 to 5 wt % (by weight based on the total weight
of the oral care composition).
[0028] Xanthan gum is a fermentation product prepared by action of
the bacteria of the genus Xanthomonas upon carbohydrates. Four
species of Xanthomonas, namely X.campestris, X. phaseoli,
X.malvocearum and X.carotae are reported in the literature to be
the most efficient gum producers.
[0029] Xanthan gum may be generally characterised as an anionic
heteropolysaccharide, with a primary structure consisting of
repeating pentasaccharide units formed by two glucose units, two
mannose units, and a glucuronic acid unit. These repeating
pentasaccharide units give xanthan gum its characteristic backbone,
which consists of (1.fwdarw.4) 6-D-glucopyranosyl units substituted
at C-3 on every other glucose residue with a charged trisaccharide
sidechain. The trisaccharide sidechain consists of a D-glucuronic
acid unit between 2 D-mannose units. Slightly less than half (about
40%) of the terminal D-mannose residues contain a pyruvic acid
residue linked via keto groups to the four and six positions, and
the D-mannose linked to the main chain mostly contains an acetyl
group at position O-6. Some side chains may be missing. The acetate
and pyruvate contents are variable on the side chain, and depend on
the bacterial strains and on the fermentation conditions used to
produce the gum.
[0030] Xanthan gum generally has a molecular weight of from 1
million to 50 million. Its viscosity generally ranges from 850 to
1,700 mPas (when measured at 25.degree. C. using a 1% solution of
the gum in 1% KCl, on a viscometer of the Brookfield LV type, at 60
rpm using Spindle No. 3).
[0031] Xanthan gum is available from several commercial suppliers
such a RT Vanderbilt Company and CP Kelco. Examples of suitable
xanthan gums are Keltrol.RTM., Keltrol.RTM. F, Keltrol.RTM. T,
Keltrol.RTM. TF, Xantural.RTM. 180 and Vanzan.RTM. NF.
[0032] The amount of xanthan gum in the composition of the
invention preferably ranges from 0.05 to 1.5 wt %, more preferably
from 0.1 to 0.9 wt % (by weight based on the total weight of the
oral care composition).
[0033] In addition to the xanthan gum as described above, other
polymeric thickening agents may be present in the composition of
the invention. Such additional polymeric thickening agents may be
of natural or synthetic origin, with a molecular weight typically
ranging from 1,000 up to about 5,000,000. Examples of such
materials include carboxyvinyl polymers (such as polyacrylic acids
cross-linked with polyallyl sucrose or polyallyl pentaerythritol),
hydroxyalkyl cellulose derivatives (such as hydroxyethyl cellulose,
hydroxypropyl cellulose, hydroxyethylpropyl cellulose,
hydroxybutylmethyl cellulose and hydroxypropylmethyl cellulose),
water soluble salts of cellulose ethers (such as sodium
carboxymethyl cellulose and sodium carboxymethyl hydroxyethyl
cellulose, polyvinylpyrrolidone, polyethylene glycols, and mixtures
thereof.
[0034] However, we have found that the xanthan gum as described
above is a surprisingly effective structurant for the composition
of the invention. Accordingly it is not generally necessary to
include significant quantities of additional polymeric thickening
agents. Preferably the level of such materials is no more than 0.5
wt %, more preferably no more than 0.1 wt %, most preferably no
more than 0.01 wt %, ideally 0 wt % (by total weight additional
polymeric thickening agents based on the total weight of the
composition).
Product Form and Optional Ingredients
[0035] The oral care composition of the invention is used to clean
the surfaces of the oral cavity.
[0036] Accordingly, preferred product forms for compositions of the
invention are those which are suitable for brushing and/or rinsing
the surfaces of the oral cavity.
[0037] The composition of the invention is most preferably in the
form of a dentifrice. The term "dentifrice" denotes an oral
composition which is used to clean the surfaces of the oral cavity.
Such a composition is not intentionally swallowed for purposes of
systemic administration of therapeutic agents, but is applied to
the oral cavity, used to treat the oral cavity and then
expectorated. Typically such a composition is used in conjunction
with a cleaning implement such as a toothbrush, usually by applying
it to the bristles of the toothbrush and then brushing the
accessible surfaces of the oral cavity.
[0038] Preferably the dentifrice is in the form of an extrudable
semi-solid such as a cream, paste or gel (or mixture thereof).
[0039] A composition according to the invention (such as a
dentifrice) will generally contain further ingredients to enhance
performance and/or consumer acceptability, in addition to the
ingredients specified above.
[0040] For example, being non-aqueous, the composition of the
invention is particularly suitable as a vehicle for oral care
actives which may be physically or chemically incompatible with
water, or which may function less efficiently in an aqueous
environment.
[0041] Specific examples of oral care actives which may be
particularly suitable for inclusion in the compositions of the
invention are:
water-soluble or sparingly water-soluble sources of zinc ions such
as zinc chloride, zinc acetate, zinc gluconate, zinc sulphate, zinc
fluoride, zinc citrate, zinc lactate, zinc oxide, zinc
monoglycerolate, zinc tartrate, zinc pyrophosphate and zinc
maleate; oral care enzyme systems such as hydrogen peroxide
producing enzyme systems (e.g. the oxidoreductase enzyme glucose
oxidase), amyloglucosidase, dextranase and/or mutanase, (optionally
in the presence of zinc ion providing compounds and/or
8-hydroxyquinoline derivatives), lactoperoxidase, lactoferrin,
lysozyme and mixtures thereof; fluoride sources such as sodium
fluoride, stannous fluoride, sodium monofluorophosphate, zinc
ammonium fluoride, tin ammonium fluoride, calcium fluoride, cobalt
ammonium fluoride and mixtures thereof; plant-derivable
antioxidants such as flavonoid, catechin, polyphenol, and tannin
compounds and mixtures thereof; antioxidant vitamins such as
tocopherols and/or derivatives thereof, ascorbic acid and/or
derivatives thereof and mixtures thereof.
[0042] A particularly preferred class of oral care active for
inclusion in the compositions of the invention includes agents for
the remineralisation of teeth. The term "remineralisation" in the
context of the present invention means the in situ generation of
hydroxyapatite on teeth.
[0043] A specific example of a suitable agent for the
remineralisation of teeth is a mixture of a calcium source and a
phosphate source which, when delivered to the teeth results in the
in situ generation of hydroxyapatite on teeth.
[0044] Illustrative examples of the types of calcium source that
may be used in this context (hereinafter termed "remineralising
calcium sources") include, for example, calcium phosphate, calcium
gluconate, calcium oxide, calcium lactate, calcium
glycerophosphate, calcium carbonate, calcium hydroxide, calcium
sulphate, calcium carboxymethyl cellulose, calcium alginate,
calcium salts of citric acid, calcium silicate and mixtures
thereof. Preferably the remineralising calcium source is calcium
silicate.
[0045] The amount of remineralising calcium source(s) (e.g. calcium
silicate) in the composition of the invention typically ranges from
1 to 30%, preferably from 5 to 20% by total weight remineralising
calcium source based on the total weight of the oral care
composition.
[0046] Illustrative examples of the types of phosphate source that
may be used in this context (hereinafter termed "remineralising
phosphate sources") include, for example, monosodium dihydrogen
phosphate, disodium hydrogen phosphate, sodium pyrophosphate,
tetrasodium pyrophosphate, sodium tripolyphosphate, sodium
hexametaphosphate, potassium dihydrogenphosphate, trisodium
phosphate, tripotassium phosphate and mixtures thereof. Preferably
the remineralising phosphate source is a mixture of trisodium
phosphate and sodium dihydrogen phosphate.
[0047] The amount of remineralising phosphate source(s) (e.g.
trisodium phosphate and sodium dihydrogen phosphate) in the
composition of this invention typically ranges from 2 to 15%,
preferably from 4 to 10% by total weight remineralising phosphate
source based on the total weight of the oral care composition.
[0048] Mixtures of any of the above described materials may also be
used.
[0049] Compositions of the present invention may also contain
further optional ingredients customary in the art such as
anticalculus agents, buffers, flavouring agents, sweetening agents,
colouring agents, opacifying agents, preservatives, antisensitivity
agents, antimicrobial agents and the like.
Process
[0050] The invention also provides a process of preparing a
non-aqueous oral care composition suitable for cleaning the
surfaces of the oral cavity, the process comprising the steps of
forming a mixture comprising ingredients (a) to (d) (as defined
above).
[0051] A preferred process according of the invention comprises the
following steps: [0052] (i) forming a mixture of the organic polyol
(a) and the xanthan gum (d) and heating the mixture (preferably to
a temperature above 50.degree. C.) to disperse the xanthan gum;
[0053] (ii) adding powdered ingredients (preferably the abrasive
cleaning agent (b) and/or the surfactant (c)) to the mixture
obtained in (i), and [0054] (iii) cooling the mixture obtained in
(ii).
[0055] Preferably, other optional ingredients selected from
fluoride sources and/or agents for the remineralisation of teeth
(such as calcium silicate, as further described above) are added
between steps (i) and (ii).
[0056] Other optional ingredients such as flavourings may suitably
be added after step (iii) to form the final non-aqueous oral care
composition.
[0057] The invention is further illustrated with reference to the
following, non-limiting Example.
EXAMPLE
Example 1
[0058] The following formulation illustrates a dentifrice
composition according to the invention:
TABLE-US-00001 Ingredient (wt %) Glycerol (99.5% a.i.) 67.4 Xanthan
gum 0.5 Trisodium phosphate anhydrous 3.5 Monosodium dihydrogen
phosphate 3.2 Sodium monofluorophosphate 1.1 Sodium saccharin 0.2
Flavour 1.1 Calcium silicate 15 Sorbosil .RTM.AC77 (ex PQ Corp.)
6.0 Sodium lauryl sulphate 2.000
[0059] Viscosity measurements were performed on the above
formulation using a rheometer, and a rheological profile plotted in
the form of viscosity versus shear stress. The rheological profile
obtained showed a relatively high viscosity plateau at low shear
stress (i.e. between 10,000 and 100,000 Pas at shear stresses of 10
Pa or less), and a shear-thinning behaviour with a relatively low
viscosity at high shear stress (i.e between 10 and 100 Pas at shear
stresses between 1000 and 10000 Pa). These rheological
characteristics are highly desirable for dentifrice compositions
and compare well with conventional aqueous dentifrices.
* * * * *